2 Crows Answered in About a Fifth of a Second, and Nobody Was Even Rushing Them

Two carrion crows named Iggy and Lemmy have posted reaction times that would make most primates look a little sluggish. In a classic laboratory test of visual decision-making, the birds picked an answer in about 235 milliseconds on average. That is roughly twice as fast as monkeys or humans have been observed to do in earlier studies of the same task, and the crows did it without getting sloppier.¹

The study, “Ultrarapid decision-making in an avian brain,” was published in the journal Science by Schmidbauer and Andreas Nieder of the University of Tübingen in Germany.¹ It matters for two reasons. It adds to the evidence that “bird brain” is a poor insult. It also shows that a brain built very differently from ours can carry out fast decisions in a way that matches what scientists expect from primates.

Two limits belong right up front. The research involved just two crows. And the speed comparison is with monkey and human results from earlier studies, not a head-to-head contest in the same lab.³

How the test works

The crows learned a perceptual decision task that researchers have used with monkeys for about three decades. A screen shows a field of moving dots. Most of them drift one way, and the crow pecks the side of the screen the majority is heading toward. A correct answer earns a mealworm.³

After thousands of trials, the birds averaged 235 milliseconds per decision, which NPR rounded to about a fifth of a second, with about 74 percent accuracy. That accuracy is comparable to primates in earlier studies.³⁴

When the motion was obvious, the crows were right nearly 100 percent of the time. When the dots were hard to read, they still did better than chance.²

What was happening inside the crows’ heads

The team recorded from the nidopallium caudolaterale, an associative area of the bird brain that is comparable to the prefrontal cortex in humans.²

About 70 milliseconds after the dots appeared, neurons in that area were already signaling which way the bird would choose. That came about 170 milliseconds before the peck. In other words, the answer showed up in the crow’s brain well before its beak reached the screen.¹

The activity built up gradually until it hit a decision threshold, and it climbed in step with how strong the motion evidence was.¹² That rising pattern resembles decision signals known from primates, even though birds do not have the layered cortex that mammals do.

“These findings show that neuronal dynamics in the avian brain are consistent with established models of decision-making in humans and non-human primates,” Nieder said in the university’s announcement.²

“Consistent with” is the key phrase. The crows’ brains fit the same models, which is not the same as saying they work identically to ours.

Self-paced, and maybe faster still

NPR described a crow’s brain as about the size of a walnut. Nieder was blunt about how birds have been judged. “For a long time, birds have been considered to be dumb creatures, which is totally wrong,” he told NPR.⁴

He also noted that the crows set their own pace during testing, so they may be able to go even faster if pushed.⁴